A greenhouse experiment was conducted to evaluate the potential role of arbuscular mycorrhizal fungi (AMF) in encouraging revegetation of copper (Cu) mine tailings. Two native plant species, Coreopsis drummondii and Pteris vittata, together with a turf grass, Lolium perenne and a leguminous plant Trifolium repens associated with and without AMF Glomus mosseae were grown in Cu mine tailings to assess mycorrhizal effects on plant growth, mineral nutrition and metal uptake. Results indicated that symbiotic associations were successfully established between G. mosseae and all plants tested, and mycorrhizal colonization markedly increased plant dry matter yield except for L. perenne. The beneficial impacts of mycorrhizal colonization on plant growth could be largely explained by both improved P nutrition and decreased shoot Cu, As and Cd concentrations. The experiment provided evidence for the potential use of local plant species in combination with AMF for ecological restoration of metalliferous mine tailings. 相似文献
Land use change resulted in land degradation is a focus of research on global environmental changes and plays a significant
role in the stability and economic development of oases in arid regions of China. Jinta Oasis, a typical oasis of temperate
arid zone in northwestern China, was investigated to assess land-use change dynamics during 1988–2003 with the aid of satellite
remote sensing and GIS, and to explore the interaction between these changes and oasis environment. Six land-use types were
identified, namely: cropland, forestland, grassland, water, urban or built-up land, and barren land. The results indicate
that cropland, urban/built-up land, and barren land increase greatly by 30.03, 13.35, and 15.52 km2, respectively; but grassland and forestland areas decrease rapidly by 58.06, and 1.76 km2, respectively. These results also show that obvious widespread changes in land-use occur within the whole oasis over the
study period and result in severe problems of environmental degradation (i.e. land desertification, decline of groundwater,
and vegetation degeneracy). 相似文献
In order to evaluate the combined effect of adsorption and biodegradation of H(2)S on activated carbon surface in biotrickling filtration, four laboratory-scale biofiltration columns were operated simultaneously for 120h to investigate the mechanisms involved in treating synthetic H(2)S streams using biological activated carbon (BAC). The first three columns (A, B, C) contained a mixture of activated carbon and glass beads, with the carbons (BAC or virgin activated carbon (VAC)) and conditions (with or without liquid medium recirculation) differentiated. The last column (D) used 100% glass beads with liquid medium recirculation. Air streams containing 45ppmv H(2)S were passed through the columns at 4s of gas retention time (GRT) and liquid flow rate was set at 0.71mlmin(-1). Column D got its breakthrough in 3min of operation, indicating a negligible contribution of glass beads to the adsorption of H(2)S. The removal efficiency (RE) of Columns B and C using VAC dropped quickly to 30% within the first 8h, and afterwards continued to drop further but slowly. Column A using BAC stayed at 25% of RE throughout the operation time. A thorough investigation of the H(2)S oxidation products, i.e., various S species in both aqueous (recirculation media) and solid phases (BAC and VAC), was conducted using ICP-OES, IC, XRF, and CHNS elemental analyzer. BAC demonstrated a better performance than columns with adsorption only. Water film was found to enhance H(2)S removal. The percentage of sulphate in the total sulphur of the BAC system improved to twice of that of VAC system, indicating sulphate is the main product of H(2)S biofiltration. The observed pH drop in BAC system double confirmed that the presence of biodegradation in the biofilm over carbon surface did profound effect on the oxidation of H(2)S, compare to the systems with adsorption only. 相似文献
Hexachlorocyclohexanes (HCHs) were produced and used in large quantity worldwide and are common soil pollutants. In this study, desorption of α-HCH and γ-HCH from two soil samples collected from a historical pesticide plant in Tianjin, China, was examined. As a comparison, desorption of freshly sorbed γ-HCH was examined, using five typical Chinese soils. Strong resistant desorption was observed for both historically contaminated and freshly contaminated soils, and desorption results were well modeled with a biphasic desorption isotherm. The unique thermodynamic characteristics associated with the desorption-resistant fraction indicated that physical constraint within soil organic matrices was likely the predominant mechanism controlling resistant desorption. Resistant desorption could have significant effects on fate and exposure of HCHs in soil environment. More accurate biphasic desorption models that take into account of the resistant desorption can be used to facilitate regulating, management and remediation of HCH-contaminated sites. 相似文献
Environmental Science and Pollution Research - Saline loess is an important cause of environmental geo-issues in northwest China. In this research, electrical resistivity of loess with different... 相似文献
Journal of Material Cycles and Waste Management - MgO-based cementitious material (MCM) is a potential green substitute for solidifying municipal solid waste incineration fly ash (MSWI FA). Sodium... 相似文献
Microplastics (MPs) have become a hot issue of environmental pollution. However, insufficient evidence exists regarding the distributions and fates of MPs in terrestrial environment, especially in farmlands. The distributions of MPs in paddy fields were investigated in Xiangtan City, a typical rice production area in China. The abundance of MPs in paddy seedling raising fields was 3805?±?511 n·kg?1, which increased by approximately 9 times than that in common paddy fields. Transparent films became the dominant forms due to the huge usage of mulching films, corresponding to that the proportion of polyvinyl chloride (PVC) increased to 17% there. Moreover, an industrial plant nearby also contributed considerably to the MP pollution; the proportion of PVC (33%) in the paddy fields nearby increased to approximately 4 times of common paddy fields, while polyvinyl alcohol (PVA; 13%) used as an important chemical raw material to synthesis in various applications was uniquely detected there. These results highlight the input of MPs from agricultural and industrial activities in farmlands. Their contributions to the MP pollution in farmlands should be continuously investigated.
Environmental Science and Pollution Research - A Pyroprobe 5000 pyrolyzer connected to a gas chromatography-time-of-flight mass spectrometry (Py-GC-TOF–MS) was used to analyze the... 相似文献